when using CURL_AUTH_ANY" (http://curl.haxx.se/bug/view.cgi?id=1945240).
  The problem was that when libcurl rewound a stream meant for upload when it
  would prepare for a second request, it could accidentally continue the
  sending of the rewound data on the first request instead of on the second.
  Ben also provided test case 1030 that verifies this fix.